The present invention relates generally to a spindle assembly for a rotary grass trimmer.
More particularly, this invention pertains to an adjustable spindle assembly for a push-type rotary grass trimmer that includes a mow ball rotatably connected to a spindle shaft and allows the attachment of cutting strings or filaments without the use of tools.
Although spindle assemblies for rotary grass trimmers are known in the art, the current versions have several problems. For example, U.S. Pat. No. 5,313,770, issued to Smothers on May 24, 1994 and entitled “JamProof Rotary Weed Cutter,” discloses a push-type grass trimmer having a spool rigidly connected to a drive shaft. The shaft and spool are driven at a high rate of speed by a motor and, when the trimmer is used, the spool comes into contact with the ground a significant amount of time. As a result, the spool rubs against the ground, wears down, and must be replaced. This result is undesirable because replacing the spool costs time and money. As a result, there is a need for a spindle assembly that reduces the amount of wear on the spool when the spool is in use.
Current spindle assembles also require the use of tools to secure the cutting string or filament to the spool and to adjust the cutting height of the string. U.S. Pat. No. 5,862,655, issued to Altamirano et al. on Jan. 26, 1999 and entitled “Adjustable Mowing and Trimming Apparatus,” discloses a push-type grass trimmer that includes an adjustable trimmer head that is connected to a spindle head using a threaded fastener, i.e., a bolt and nut. In addition, the cutting string is also connected to the trimmer head using a bolt and nut. U.S. Pat. No. 6,052,974, issued to Harb on Apr. 25, 2000 and entitled “Adjustable Height Head For String Trimmer,” also discloses a string trimmer that uses bolts to secure the cutting string to the trimmer head and to secure the adjustable trimmer head in place.
Since bolts are used to secure the trimmer head and cutting string, a separate tool, such as a wrench, must be used to loosen or tighten the bolts in order to adjust the cutting height or to replace the cutting string. The requirement for a separate tool is undesirable because, in some cases, the required tool may not be readily available. Furthermore, the use of a bolt and nut to secure the trimmer head and cutting string increases the amount of time it takes to replace the cutting string or adjust the height of the trimmer head. Thus, there is a need for a spindle assembly that includes a means for adjusting the cutting height of the trimmer head and attaching the string to the trimmer head that does not require the use of a separate tool.
What is needed, then, is a spindle assembly that reduces the amount of wear on the spool and eliminates the need for a separate tool to adjust the cutting height and to replace the cutting string.